Network Adapter could not establish the connection
Error: While trying to connect to database from SQL* PLUS
Status: Failure - Test Failed: IO Error: The Network Adapter could not establish the connection
Solution:
1. Check the host, SID and port entry in Listener.ora file
2. Stop the firewall
Stop the Firewall:
[oracle@test test_test]$ systemctl stop firewalld
==== AUTHENTICATING FOR
org.freedesktop.systemd1.manage-units ===
Authentication is required to manage system services or
units.
Authenticating as: root
Password:
==== AUTHENTICATION COMPLETE ===
[oracle@testr12 testr12_test]$ systemctl disable firewalld
==== AUTHENTICATING FOR
org.freedesktop.systemd1.manage-unit-files ===
Authentication is required to manage system service or unit
files.
Authenticating as: root
Password:
==== AUTHENTICATION COMPLETE ===
Removed symlink
/etc/systemd/system/basic.target.wants/firewalld.service.
Removed symlink
/etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
==== AUTHENTICATING FOR
org.freedesktop.systemd1.reload-daemon ===
Authentication is required to reload the systemd state.
Authenticating as: root
Password:
==== AUTHENTICATION COMPLETE ===
[oracle@test test_test]$
